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Cone Penetrometer Assessment Report 4
<br /> Ranch Market 23569 South Santa Fe Road,Riverbank Cahforma November 20,2001
<br /> • Water samples collected from domestic wells have been analyzed for the presence of BTEX,
<br /> TPHg, five oxygenates, 1,2-DCA, and EDB Since water samples collected from DW-2
<br /> contained reportable concentrations of MtBE, the well was taken out of service
<br /> On April 6, 2000, SECOR's field technician interviewed the property owners or renters
<br /> associated with the four domestic water wells and found that water pumped from wells DW-1,
<br /> DW-3, and DW-4 was used for irrigation and domestic use All parties interviewed indicated
<br /> they were drinking bottled water
<br /> Replacement of Domestic Well DW-2
<br /> On January 11, 2001, SECOR oversaw destruction of domestic well DW-2, located south of
<br /> Ranch Market (Figure 2) Details of the well destruction are described in SECOR's DW-2 Well
<br /> Destruction Report, dated January 23, 2001
<br /> On December 20, 2000, SECOR began oversight of the installation of domestic well DW-2R,
<br /> the replacement domestic well for DW-2 From December 28, 2000, to January 5, 2001, the
<br /> dedicated well pump, pressure tank, concrete pad, and well-related underground electrical and
<br /> water service line were installed Details of the well installation are described in SECOR's
<br /> Domestic Well Installation Report (DW-2R), dated February 1, 2001
<br /> On January 8, 2001, SECOR sampled DW-2R and submitted the water sample to Kiff
<br /> Analytical for BTEX, TPHg, oxygenates, 1,2-DCA, and EDB using EPA method 8260B The
<br /> sample was also analyzed at CLS for Nitrate/Nitrite using EPA method 300 0 SECOR
<br /> collected confirmation water samples from DW-21Z on January 11, 2001, and again on January
<br /> 15, 2001 Analytical data is summarized in Table 3
<br /> After review of the confirmation samples, the San Joaquin County Environmental Health
<br /> Department (SJCEHD)requested the well be brought online On January 18, 2001, SECOR
<br /> met with Mr Michael Infurna with SJCEHD for the final inspection of well DW-2R The
<br /> water service from the Aero Pure Water supply tank was disconnected and the water valve was
<br /> opened, allowing DW-2R to supply water to the home on the Pantoja Property
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<br /> Hydrogeology
<br /> The depth to groundwater ranges from 26 to 32 feet bgs in the on-and-offsite wells
<br /> Historically, groundwater flow direction has been southerly Groundwater gradient was 0 005
<br /> foot per foot in the second quarter 2001 Surface drainage is to the southeast, towards the
<br /> Stanislaus River, located approximately 750 feet south of the Site
<br /> Litholoey
<br /> Based on the description of the soil samples collected from the previous soil borings, and based
<br /> on the CPT logs, the lithology at the Site consists mainly of sands and silts with varying
<br /> File Stanch MarketlReports\Rb-CPT Install
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